2) Debian GNU/Linux, with only the main archive area enabled. The "contrib" and "non-free" areas must not be enabled when testing hardware. Double-check this by running apt-cache policy. The only package archive area mentioned in the output should be main.

h-node lists only hardware that works with free drivers and without non-free firmware. Other GNU/Linux distributions (or Debian with contrib, non-free, or some 3rd-party archives enabled) include non-free firmware files, so they cannot be used for testing.